Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
thanh tran » thanh trang, thanh toan, thanh tra
cuong cong » luong cong, duong cong, dung cong
dai khoang » da khoang, dai khong, tao khoang
cong cong » cong dong, trong cong, dung cong
dan khoan » dan khoa, toan khoan, cac khoan
tran van » luan van

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu xanh - thanh tran van ((cuong cong) OR (cong cong)) ((dan khoan) OR (dai khoang)) cam~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc thieu xanh - thanh tran van ((cuong cong) or (cong cong)) ((dan khoan) OR (dai khoang)) cam~".
• Adding a wildcard symbol may retrieve word variants: toc thieu xanh - thanh tran van ((cuong cong) or (cong cong)) ((dan khoan) OR (dai khoang)) cam*.